System for arresting the movement of objects traveling along a defined path

ABSTRACT

An emergency system for arresting the movement of a traveling object such as an elevator car wherein the momentum of the object is absorbed by the physical extension of elongated metal members engaged by the moving object. Two or more of the elongated metal members are provided on each side of the path of the object with one end of such members being restrained against movement in at least one direction and the other end being engaged by a projection provided for that purpose on the object and free to move with the object and impart extension to the metal members.

O United States Patent [151 3,674,117

Sjostrom, deceased et al. 1 July 4, 1972 [54] SYSTEM FOR ARRESTING THE [56] References Cited MOVEMENT 0F OBJECTS TRAVELING UNITED STATES PATENTS ALONG A DEFINED PATH 729,022 5/1903 Venn I72] Inventors: Costa sjostmm, deceased late of Mark 3,537,550 3/1970 Ely ..2l2/69 nadsvage? F" 8108' Primary ExaminerHarvey C. Homsby J s-lostmmi Bjorn s-lostmm AttorneyWilliam J. Daniel heirs, all of Marknadsvagen 63, 183 Taby 34, Sweden 57 ABSTRACT Filed! 7, 1970 An emergency system for arresting the movement of a traveling object such as an elevator car wherein the momentum of [2]] Appl' 78855 the object is absorbed by the physical extension of elongated metal members engaged by the moving object. Two or more of 52 us. Cl ..187/67, 187/73 the elongated metal members are Provided on each Side of the [51] Int. Cl ..B66b 5/28 P of the object with one end of Such members being [58] Field of Search 187/67 71 1 73 267/10 restrained against movement in at least one direction and the 2 7 1 73 other end being engaged by a projection provided for that purpose on the object and free to move with the object and impart extension to the metal members.

3 Claims, 2 Drawing Figures SYSTEM FOR ARRESTING THE MOVEMENT OF OBJECTS TRAVELING ALONG A DEFINED PATH The present invention relates to a system for arresting the movement of an object travelling along a defined path and more particularly to systems of this type in elevator shafts and hoistways for arresting the movement of the elevator car or the like travelling therein in the event of the car overriding predetermined safe limit positions.

Conventional arresting systems used for this purpose generally comprise buffers and wedge guide structures, arranged to absorb the kinetic energy of the moving car in an emergency, thereby bringing the car to a stop. These devices, however, do not completely fulfil the stringent requirements placed on such emergency stopping systems. Furthermore, the task of putting known arresting systems of the type referred to into a reliable working condition upon being used is a relatively complicated one and time consuming. In contradistinction to this, the arrangement of the present invention can be made serviceable after use quickly and surely and oflers a much safer basis of calculation than do present day arresting systems. Furthermore, the elevator car or the like, when arrested by the arresting system of the present invention, is brought to a smooth stop, thereby greatly reducing the amount of damage otherwise caused by overtravel.

The object of the present invention is thus to provide an arresting system for objects moving along a defined path, which brings the objects to a stop smoothly and gently and which can be made serviceable in a quick and reliable manner.

This is achieved by means of the system described in the appended claims and characterized by a number of extensible elongated metal members extending along at least a part of at least two opposing sides of said path, stirrup members firmly attached to at least one end of each extensible member and freely seated for movement in one direction only on brackets firmly secured on said sides of said path, and stirrup engaging means firmly mounted on the moving object and adapted to move respective stirrups out of engagement with their respective brackets in the direction of movement of the object, thereby to stretch the extensible members and in doing so arrest the movement of said object.

The invention will now be described in more detail with reference to the accompanying drawing, in which FIG. 1 is a diagrammatical front view of a hoistway provided with the arresting system of the invention and FIG. 2 is a section taken along the line A A in FIG. 1.

In FIG. 1 there is shown a movable vehicle 1, which in the illustrated embodiment is conceived to be an elevator car, suspended in the hoistway by means of a cable la, driven by a winching mechanism (not shown). Arranged along at least part of opposing walls of the hoistway are metal rods 3. These rods are suitably of stainless steel and should be capable of being stretched to at least half their length again before fracture occurs. Securely attached to at least one end of each rod is a stirrup member 4, which rests freely in an open groove (not shown) arranged in a bracket 5. The brackets 5 are firmly mounted on the walls of the hoistway at a predetermined distance from the safe stop limit for the elevator car 1. Mounted on the upper portion of the elevator car 1 are outwardly projecting shoes 2, arranged to engage the stirrups 4 when the car passes the safe limit position.

The method of operation of the arresting system of the invention will be quite apparent from the aforegoing and the drawing. When the object, in the exemplary embodiment the elevator car, moves past the safe limit position, the shoes 2 engage the stirrups 4, lifting the stirrups from the open grooves in brackets 5, whereupon continued movement of the car stretches the rods 3, which absorb the kinetic energy of the car and cause it to stop.

In accordance with one embodiment of the invention, the extensible members are secured to the walls of the hoistway in a manner which causes them to converge towards the arresting position, i.e., the position at which the shoes 2 engage the stirrups 4.

In accordance with another embodiment of the invention, the extensible members 3 may extend parallel with the walls of the hoistway between the arresting positions, although it must be ensured that while pennitting the stirrups to move away in one direction the brackets will restrain the stirrups against movement in the other direction.

Obviously, although the system has been described with reference to only one arrangement of brackets, stirrups, shoes and extensible members, this arrangement can be duplicated at other positions in the hoistway.

Moreover, irrespective of the manner in which the extensible members extend along the hoistway, i.e., whether converging or parallel, it should be ensured that their attachment is such that they can be readily dismantled and replaced upon being used.

Lastly, although reference has been made to extensible members in the form of metal rods, it will be understood that these may be replaced by other suitable, elongated extensible means such as wires, metal strips and the like.

What we claim is:

1. An emergency system for arresting in at least one direction the movement of objects travelling along a defined path, comprising a plurality of elongated metal members formed of a metal capable of undergoing significant extension by plastic deformation before rupture and extending along at least a portion of at least two opposing sides of said path, means retaining one end of each of said metal members fixed against movement in at least one direction, a stirrup member attached to the other end of each metal member, bracket means fixed adjacent said path for releasably receiving said stirrup member for free movement in a direction toward which the first end of said metal member is fixed against movement, and stirrup engaging means mounted on the moving object and adapted to engage the corresponding stirrup member and displace the same out of their respective brackets in the direction of movement of the object, thereby to stretch the metal members and thus arrest the movement of said object.

2. A system according to claim 1 wherein the longitudinal axes of the metal members on opposing sides of the path diverge from the path in the direction of the fixed ends thereof so as to permit free passage of the stirrup engaging means past the fixed ends of the members remote from the arresting position.

3. A system according to claim 1, wherein the longitudinal axes of extensible members on opposing sides extend parallel to one another. 

1. An emergency system for arresting in at least one direction the movement of objects travelling along a defined path, comprising a plurality of elongated metal members formed of a metal capable of undergoing significant extension by plastic deformation before rupture and extending along at least a portion of at least two opposing sides of said path, means retaining one end of each of said metal members fixed against movement in at least one direction, a stirrup member attached to the other end of each metal member, bracket means fixed adjacent said path for releasably receiving said stirrup member for free movement in a direction toward which the first end of said metal member is fixed against movement, and stirrup engaging means mounted on the moving object and adapted to engage the corresponding stirrup member and displace the same out of their respective brackets in the direction of movement of the object, thereby to stretch the metal members and thus arrest the movement of said object.
 2. A system according to claim 1 wherein the longitudinal axes of the metal members on opposing sides of the path diverge from the path in the direction of the fixed ends thereof so as to permit free passage of the stirrup engaging means past the fixed ends of the members remote from the arresting position.
 3. A system according to claim 1, wherein the longitudinal axes of extensible members on opposing sides extend parallel to one another. 